and there you go, a negative, one instance. I have worked in the RV industry, currently as a tech in a dealership. I asked around about how many issues with slides, and while they do happen, it is not that common. A royal pain to be sure, but so are leveling jacks, things happen to them as well. Engines are pretty durable, but water heaters break. Face it, any rv is a house on wheels in a perpetual earthquake and things can go wrong. Should I say can? Something will go wrong, maybe not while you own it, but someday something will.
I have replaced and repaired water heaters, from an older one developing a leak, to newer ones that have a thermostat go bad.
To his point, having 28' and no slide, we had a 35' with no slide for 10 years, some of those years full timing in it. We could have gone an extra 10 years with no slide, but now that we have it, we love it, and our (if) next coach will have at least 2. We have a living room slide, but a bedroom slide will make it that much more roomy.
Good luck in your search and your decision.